NGC 7184 is abarred spiral galaxy located in the constellationAquarius. It is located at a distance of circa 100 millionlight years fromEarth, which, given its apparent dimensions, means that NGC 7184 is about 236,000 light years across. It was discovered byWilliam Herschel on October 28, 1783.[2]
NGC 7184 has a small, bright nucleus and an ellipticalbulge, whose major axis is aligned with the major axis of the disk. There is a bar along the minor axis of the bulge, but the high inclination of the galaxy makes its presence uncertain. From the bar emanate two tightly wound symmetricalspiral arms that form a bright inner ring.[3] The diameter of the ring along its major axis is 1.71 arcminutes.[4] The arms featureHII regions, and as they emerge from the ring are flocculent, based on the HII distribution, while they begin to split again at the outermost part of the galaxy.[5] Dust lanes are observed in the inner part of the disk.[6]
An outlying HII region has been discovered near NGC 7184. It is located on the major axis of the optical disk, on the northeasterly receding edge. Its size is estimated to be 270 pc at the distance of the galaxy and itsHα luminosity, 1037.6 erg s−1. It could be an isolated extension of a spiral arm.[7]
SN 1984N was discovered visually byRobert Evans at magnitude 14, 60" east and 65" north of the nucleus on July 20, 1984. Its discovery was confirmed by T. Cragg at theAnglo-Australian Observatory.[8] Initially it was thought to be a variable star in our galaxy,[9] but later study of the object revealed it was indeed a supernova.[10][11] It was identified asType I.[12]
NGC 7184 is the foremost galaxy of a smallgalaxy group known as the NGC 7184 group, which also includesNGC 7183.[13] A satellite galaxy lies 3 arcminutes to the south, at a projected separation of 28 kpc.[14]
^Seligman, Courtney."NGC 7184".Celestial Atlas. Retrieved19 November 2018.
^Eskridge, Paul B.; Frogel, Jay A.; Pogge, Richard W.; Quillen, Alice C.; Berlind, Andreas A.; Davies, Roger L.; DePoy, D. L.; Gilbert, Karoline M.; Houdashelt, Mark L.; Kuchinski, Leslie E.; Ramirez, Solange V.; Sellgren, K.; Stutz, Amelia; Terndrup, Donald M.; Tiede, Glenn P. (November 2002). "Near-Infrared and Optical Morphology of Spiral Galaxies".The Astrophysical Journal Supplement Series.143 (1):73–111.arXiv:astro-ph/0206320.Bibcode:2002ApJS..143...73E.doi:10.1086/342340.S2CID15491635.
^Comerón, S.; Salo, H.; Laurikainen, E.; Knapen, J. H.; Buta, R. J.; Herrera-Endoqui, M.; Laine, J.; Holwerda, B. W.; Sheth, K.; Regan, M. W.; Hinz, J. L.; Muñoz-Mateos, J. C.; Gil de Paz, A.; Menéndez-Delmestre, K.; Seibert, M.; Mizusawa, T.; Kim, T.; Erroz-Ferrer, S.; Gadotti, D. A.;Athanassoula, E.; Bosma, A.; Ho, L. C. (19 February 2014). "ARRAKIS: atlas of resonance rings as known in the S4G".Astronomy & Astrophysics.562: A121.arXiv:1312.0866.Bibcode:2014A&A...562A.121C.doi:10.1051/0004-6361/201321633.S2CID119295831.
^Meurer, Gerhardt R.; Hanish, D. J.; Ferguson, H. C.; Knezek, P. M.; Kilborn, V. A.; Putman, M. E.; Smith, R. C.; Koribalski, B.; Meyer, M.; Oey, M. S.;Ryan-Weber, E. V.; Zwaan, M. A.; Heckman, T. M.; Kennicutt, Jr., R. C.; Lee, J. C.; Webster, R. L.; Bland-Hawthorn, J.; Dopita, M. A.; Freeman, K. C.; Doyle, M. T.; Drinkwater, M. J.; Staveley-Smith, L.;Werk, J. (July 2006). "The Survey for Ionization in Neutral Gas Galaxies. I. Description and Initial Results".The Astrophysical Journal Supplement Series.165 (1):307–337.arXiv:astro-ph/0604444.Bibcode:2006ApJS..165..307M.doi:10.1086/504685.S2CID9655238.
^Sandage, A., Bedke, J. (1994),The Carnegie Atlas of Galaxies. Volume I, Carnegie Institution of Washington
^Werk, J. K.; Putman, M. E.; Meurer, G. R.;Ryan-Weber, E. V.; Kehrig, C.; Thilker, D. A.; Bland-Hawthorn, J.; Drinkwater, M. J.; Kennicutt, R. C.; Wong, O. I.; Freeman, K. C.; Oey, M. S.; Dopita, M. A.; Doyle, M. T.; Ferguson, H. C.; Hanish, D. J.; Heckman, T. M.; Kilborn, V. A.; Kim, J. H.; Knezek, P. M.; Koribalski, B.; Meyer, M.; Smith, R. C.; Zwaan, M. A. (1 January 2010). "Outlying H Ii Regions in H I-Selected Galaxies".The Astronomical Journal.139 (1):279–295.arXiv:0911.1791.Bibcode:2010AJ....139..279W.doi:10.1088/0004-6256/139/1/279.S2CID119161733.
^Spratt, C. E. (1987). "Visually discovered extra-galactic supernovae".Journal of the American Association of Variable Star Observers.16 (1):19–22.Bibcode:1987JAVSO..16...19S.
